The E-Sylum:  Volume 7, Number 48, November 28, 2004, Article 7

LATENT HOLOGRAM AS CURRENCY SECURITY MEASURE

  The following article by Mark Hartford is reprinted
  from the November 25, 2004 issue of the MPC GRAM,
  covering the entire World of Military Numismatics.
  See papermoneyworld.net

  "New anti-counterfeiting method discovered! At least
  by me. Yesterday, I showed a Romanian 2,000 Lei
  solar eclipse commemorative (Pick 111) to two friends
  at work. They are both really smart Physics experts,
  particularly in the field of visual, optics, coatings,
  and infrared technologies. One noted that there was a
  square in the middle of the clear window. We all
  looked at it with a magnifier. One of the gentlemen
  suggested that it could be a latent hologram. I asked
  "what in the world is that?" He reads lots of journals
  on optics and lasers, so I was surprised when he
  started looking for a laser pointer used in briefings.
  (Strangely, I had just bought my first laser pointer
  on Saturday the 20th, in order to give my talk to
  Aviation banknote talk at the IBNS meeting at the St.
  Louis PCDA show.)    When we found one, he pointed the
  laser through this square. What was projected onto the
  wall was awesome. It looks like a crescent moon with
  rays emanating from the outside of it. This is clearly
  the Sun with rays being occulted by the moon during a
  solar eclipse. This works best in a darkened room. If
  you try this, be careful not to stare directly at the
  laser. I don't think staring at the reflection off of
  white surfaces is very good for your eyes either. My
  friend tells me that this is probably put on with a
  heated metal micro-mold that contains all of the
  interference patterns imbedded, so that when strong,
  coherent light (i.e. a laser) transmits through it an
  image is created.

  I had always assumed this square was melted onto
  the surface as an additional step that counterfeiters
  would have to take. A minor additional task for a
  counterfeiter, but still a bit of a hassle. After all,
  this note catalogues for $1.50 and has a face value of
  six and a half cents (ER on 25nov04 is 30,818 lei per
  U.S. dollar). This is quite an advanced
  anti-counterfeiting technique for such a cheap note. I
  don't think making and applying these latent holograms
  would be easy for counterfeiters. The low cost of
  applying these (less than 6 & 1/2 cents in large
  quantities) is clearly an indication that polymer
  notes have yet another benefit over paper notes.

  I haven't checked what other polymer notes
  contain this feature. It will be fascinating to see
  what other beautiful images emerge from my notes and
  laser pointer in the next few days!

  Hope this wasn't already known by the community,
  otherwise, this is old news to everyone except me.?

  Wayne Homren, Editor

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